U.S. patent application number 15/504432 was filed with the patent office on 2017-08-17 for machine spindle with ejecting means.
The applicant listed for this patent is THE GLEASON WORKS. Invention is credited to William A. Curtis, Kenneth E. Glasow, Michael G. Regna, Craig R. Ronald.
Application Number | 20170232525 15/504432 |
Document ID | / |
Family ID | 54150674 |
Filed Date | 2017-08-17 |
United States Patent
Application |
20170232525 |
Kind Code |
A1 |
Curtis; William A. ; et
al. |
August 17, 2017 |
MACHINE SPINDLE WITH EJECTING MEANS
Abstract
A workholding apparatus (10) wherein a draw bar (22) effects
chucking and de-chucking of a workpiece (W) and wherein un-seating
of the workholding apparatus is effected by piston-like mechanisms
(30) located in a machine spindle (2).
Inventors: |
Curtis; William A.;
(Stanley, NY) ; Glasow; Kenneth E.; (Spencerport,
NY) ; Regna; Michael G.; (Rochester, NY) ;
Ronald; Craig R.; (Fairport, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE GLEASON WORKS |
Rochester |
NY |
US |
|
|
Family ID: |
54150674 |
Appl. No.: |
15/504432 |
Filed: |
September 4, 2015 |
PCT Filed: |
September 4, 2015 |
PCT NO: |
PCT/US2015/048637 |
371 Date: |
February 16, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62046693 |
Sep 5, 2014 |
|
|
|
Current U.S.
Class: |
279/155 |
Current CPC
Class: |
Y10S 279/901 20130101;
B23Q 7/006 20130101; B23B 31/265 20130101; B23B 31/003 20130101;
Y10T 409/309464 20150115; B23F 23/06 20130101; B23B 31/06 20130101;
B23B 2270/09 20130101 |
International
Class: |
B23B 31/00 20060101
B23B031/00; B23F 23/06 20060101 B23F023/06 |
Claims
1. A machine spindle rotatable about an axis of rotation, said
spindle comprising a spindle body having an outer end with said
outer end having an opening and an end surface surrounding said
opening, said spindle further comprising: a plurality of rod-shaped
ejecting elements located in said outer end at said end surface
with each of said rod-shaped ejecting elements being extendable
from said end surface and retractable into said end surface, said
rod-shaped ejecting elements being operable to extend from said end
surface and into contact with a surface of a workholding apparatus
located in a seated position within said spindle body, said contact
being of a force sufficient to urge said workholding apparatus from
said seated position.
2. The machine spindle of claim 1 wherein said rod-shaped ejecting
element comprises a piston.
3. The machine spindle of claim 2 wherein said piston is located
within a piston retainer.
4. The machine spindle of claim 1 wherein said rod-shaped ejecting
elements are extendable via fluid pressure.
5. The machine spindle of claim 4 further comprising said
rod-shaped ejecting elements being extendable via springs.
6. The machine spindle of claim 1 further comprising said
rod-shaped ejecting elements being retractable via springs.
7. The machine spindle of claim 1 wherein said plurality of
rod-shaped ejecting elements are spaced equidistantly about said
end surface.
8. The machine spindle of claim 1 wherein said plurality of
rod-shaped ejecting elements are spaced radially equidistantly from
said axis of rotation.
9. A method of breaking the seating contact between a machine
spindle and a workholding apparatus seated within said spindle,
said method comprising: providing a machine spindle rotatable about
an axis of rotation, said spindle comprising a spindle body having
an outer end with said outer end having an opening and an end
surface surrounding said opening, said spindle further comprising a
plurality of rod-shaped ejecting elements located in said outer end
at said end surface with each of said rod-shaped ejecting elements
being extendable from said end surface and retractable into said
end surface, extending said rod-shaped ejecting elements from said
end surface, bringing said rod-shaped ejecting elements into
contact with a surface of the seated workholding apparatus, said
contacting being of a force sufficient to urge said workholding
apparatus from the seated contact.
10. The method of claim 9 wherein said rod-shaped ejecting elements
comprise pistons.
11. The method of claim 9 wherein said extending of said rod-shaped
ejecting elements is effected by fluid pressure.
12. The method of claim 1 further comprising retracting said
rod-shaped ejecting elements.
13. The method of claim 1 wherein said retracting is effected by
springs.
Description
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 62/046,693 filed Sep. 5, 2014, the entire
disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed workholding equipment.
Specifically, the present invention discloses a workholding
apparatus for securing a workpiece in a machine tool in which the
workholding apparatus is quickly secured in, and released from, the
spindle of the machine tool.
BACKGROUND OF THE INVENTION
[0003] In metalworking operations where a workpiece is machined,
equipment of some type is necessary to hold the workpiece in
position in a machine tool so the machining process can be
successfully carried out. This type of equipment is known as
"workholding" equipment. In the production of toothed articles,
such as gears, workholding equipment can be generally categorized
as two types, chucks and arbors.
[0004] Chucks hold a workpiece by contracting a component called a
"collet" around the workpiece or a component thereof. For example,
when a bevel or hypoid pinion with integral shaft is placed in a
chuck, it is usually the shaft that is gripped by the collet which
has been reduced in diameter (i.e. contracted) to grip the shaft to
hold the pinion in position for machining. Examples of chucks for
gripping pinion shanks can be found in U.S. Pat. No. 3,083,976 to
Stark and U.S. Pat. No. 3,244,427 to Taschl.
[0005] Arbors grip a workpiece by expanding a collet into contact
with a surface of the workpiece. As an example, a bevel ring gear
is placed on an arbor and the collet is expanded until contact of
sufficient force is established with the surface of the bore of the
ring gear to hold the ring gear in position during machining. An
example of an arbor for a ring gear can be found in U.S. Pat. No.
3,735,994 to Jaehn. An arbor for expanding into contact with the
bore of a pinion can be found in U.S. Pat. No. 3,517,939 to
Jaehn.
[0006] In either chucks or arbors, the force necessary to contract
or expand the collet mechanism is provided by a draw bar (or draw
rod) in the machine tool. The draw bar is advanced and/or retracted
usually via a hydraulically operated piston. Movement of the draw
bar in the axial direction of the chuck or arbor usually causes
opposed angled surfaces of components within the workholding
equipment to slide relative to one another resulting in inward
(contracting) or outward (expanding) movement of the collet to grip
a workpiece or component part thereof. Generally, one angled
surface is found on the collet and the other angled surface is
found on an actuator attached to the draw bar or on the draw bar
itself.
[0007] Chucks and arbors are mounted for rotation in the bore of a
spindle of a machine tool. The spindle bore is usually tapered and
a similar taper is usually found on the outer surface of the chuck
or arbor. Once placed in the spindle bore, a plurality of bolts are
extended through holes in a mounting flange, located about the
spindle, and into engagement with corresponding threaded holes in
the face of the machine spindle.
[0008] Securing a chuck or arbor to a machine tool spindle, or
ejecting it from the machine tool spindle, are manually performed
operations that are very time consuming since the many bolts must
be tightened to specifications. When removing the chuck or arbor,
aside from the time necessary to loosen and remove all of the
bolts, ejector screws usually must be utilized to "break" (i.e.
un-seat) the contact between the chuck/arbor outer tapered surface
and the tapered inner surface of the spindle bore.
[0009] U.S. Pat. No. 6,260,855 to Curtis teaches a workholding
apparatus in which action of a draw bar effects gripping and
release of a workpiece but also effects the seating of a chuck or
arbor being positioned in a machine spindle as well as the
un-seating of a chuck or arbor from its seated position in a
machine spindle. The apparatus includes sets of spaced apart lugs
that must pass by similarly spaced lugs on a draw bar and sleeve
when inserting the apparatus in a spindle. Once inserted, the
apparatus is turned to align the lugs thereby establishing contact
between the apparatus and the draw bar. A stop mechanism is also
included on the draw bar to prevent inadvertent forward movement of
the draw bar when de-chucking a workpiece.
[0010] It is an object of the present invention to provide a means
to simplify the installation of a chuck or arbor in a machine
spindle and its removal from the spindle while eliminating some
components of the chuck or arbor thereby saving time and reducing
material and assembly costs.
SUMMARY OF THE INVENTION
[0011] The invention is directed to a workholding apparatus wherein
a draw bar effects chucking and de-chucking of a workpiece and
wherein un-seating of the workholding apparatus is effected by
piston-like mechanisms located in a machine spindle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an axial cross-section of a machine spindle and
chuck mechanism.
[0013] FIG. 2 is a front view of the spindle of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] The terms "invention," "the invention," and "the present
invention" used in this specification are intended to refer broadly
to all of the subject matter of this specification and any patent
claims below. Statements containing these terms should not be
understood to limit the subject matter described herein or to limit
the meaning or scope of any patent claims below. Furthermore, this
specification does not seek to describe or limit the subject matter
covered by any claims in any particular part, paragraph, statement
or drawing of the application. The subject matter should be
understood by reference to the entire specification, all drawings
and any claim below. The invention is capable of other
constructions and of being practiced or being carried out in
various ways. Also, it is understood that the phraseology and
terminology used herein is for the purposes of description and
should not be regarded as limiting.
[0015] The details of the invention will now be discussed with
reference to the accompanying drawings which illustrate the
invention by way of example only. In the drawings, similar features
or components will be referred to by like reference numbers.
Although references may be made below to directions such as upper,
lower, upward, downward, rearward, bottom, top, front, rear, etc.,
in describing the drawings, there references are made relative to
the drawings (as normally viewed) for convenience. These directions
are not intended to be taken literally or limit the present
invention in any form.
[0016] The use of "including", "having" and "comprising" and
variations thereof herein is meant to encompass the items listed
thereafter and equivalents thereof as well as additional items.
[0017] FIG. 1 shows a spindle 2 for a machine tool (not shown), for
example, a machine for grinding or cutting bevel gears such as that
disclosed in U.S. Pat. No. 6,712,566 to Stadtfeld et al. Spindle 2
is rotatable about an axis A and includes a spindle body 4 having
an inner end (not shown) and an outer end defining an outer opening
9, a tapered inside seating surface 5, flange portion 6 and an
outer end surface 8 (i.e. a front surface 8 known as a spindle
face) surrounding the outer opening 9 located about axis A at the
outer end of spindle 2.
[0018] A chuck 10 is seated in spindle 2. Chuck 10 includes a chuck
body 12 having a tapered outside surface which is complementary to
the tapered inside seating surface 5 of spindle 2. Chuck 10 further
includes a flange portion 14, contractor 16, collet 18 and draw bar
connector 20. A spindle nose 13 having an end surface 17 is
attached to chuck body 12 such as by screws (not shown). FIG. 1
further shows a machine draw bar 22, support member 24 and draw bar
collet 26.
[0019] For ejecting chuck 10 from its seated position in spindle 2,
a plurality of ejecting mechanisms 28 (preferably three) are each
located in the outer end of the spindle and are spaced, preferably
equidistantly, about spindle face 8. It is also preferred that each
ejecting mechanism 28 be spaced radially from axis A by the same
distance. See FIG. 2. Preferably, each ejecting mechanism 28
comprises an extendable-retractable rod-shaped ejecting element
such as a piston 30, for example, with each piston 30 being located
within a piston retainer 32. Preferably, a forward ejecting
(extending) movement of each piston 30 (to the left in FIG. 1),
whereby each piston 30 is extended axially outward from spindle
face 8, is effected by fluid pressure supplied via a fluid port 34
extending through the spindle body 4 to each piston 30. The
particular fluid is preferably hydraulic oil, but other fluids,
such as air, are also contemplated. If ejecting force in addition
to the supplied fluid is desired, the force of each piston may be
supplemented with springs.
[0020] A return (i.e. retracting) movement of each piston (to the
right in FIG. 1), whereby each piston 30 retracts axially into
spindle face 8, is preferably effected by one or more springs, such
as a wave spring 33, once the pressure applied via fluid port 34 is
reduced or removed. Alternatively, the return movement of each
piston may be accomplished via fluid pressure.
[0021] In operation, chuck 10 is inserted into spindle 2 via the
outer opening of the outer end of spindle 2. With work piece W
mounted in the chuck 10, draw bar 22 is activated (moved to the
right in FIG. 1) at a high pressure (e.g. 12,000 pounds-force
(53,379 Newtons)) to engage both the draw bar collet 26 and chuck
collet 18 to seat the chuck 10 and the work piece W respectively.
Both chuck 10 and work piece W are now secured to the spindle 2 for
rotation about axis A. The back face 15 of chuck flange portion 14
is located against spindle face 8. The work piece can now be
processed (e.g. grinding).
[0022] To remove the work piece W from chuck 10, draw bar 22 is
activated in opposite direction (moved to the left in FIG. 1) at
low pressure (e.g. 6,000 pounds-force (26,689 Newtons)). The force
exerted by the draw bar 22 is sufficient to disengage the chuck
collet 18 thereby releasing work piece W while being sufficiently
low so as to not affect the seating of chuck 10 in spindle 2. The
work piece W can now be removed. Another work piece is mounted into
chuck 10 and clamped by activating draw bar 22 in the opposite
direction (to the right in FIG. 1) at the low force. The process is
repeated for each successive work piece until such time as chuck 10
is to be removed.
[0023] The chuck 10 is released from its seated position in spindle
2 by actuating the three pistons 30 that are embedded in spindle
face 8 to project each piston 30 axially outward from spindle face
8. Pistons 30 exert a total force (e.g. 9,000 pounds-force (40,034
Newtons)) onto chuck flange 14 preferably in the axial direction
(A). Thus, based on the example, with three pistons, each piston
provides 3,000 pounds-force (13,345 Newtons). The total force must
be sufficient to unseat the tapered surfaces engagement between
outside tapered surface of chuck 10 and inside tapered surface 5 of
spindle 2. Once the seating contact is "broken", the chuck 10 can
be easily removed from machine spindle 2.
[0024] While the invention has been described with reference to
chucks, the invention is equally applicable to arbors. While a
bevel pinion has been illustrated, a ring gear is likewise
contemplated. While pistons are the preferred mechanisms for
ejecting a workholding mechanism from a seated position in a
spindle, any other controllable mechanism which can be located in
the spindle and be activated to exert an effective ejecting force
is contemplated by the invention. If desired, ejecting mechanisms
28 may be located in back face 15 of workholding flange portion 14
instead of in the spindle face 8.
[0025] While the invention has been described with reference to
preferred embodiments it is to be understood that the invention is
not limited to the particulars thereof. The present invention is
intended to include modifications which would be apparent to those
skilled in the art to which the subject matter pertains without
deviating from the spirit and scope of the appended claims.
* * * * *